HGF, a hetero-dimer type polypeptide produced by mesenchymal cells, is known to stimulate angiogenesis and the growth and scattering of various cells. The diverse activities of HGF are mediated by the transmembrane tyrosine kinase encoded by the receptor thereof, i.e., the proto-oncogene cMet. HGF/cMet has been reported to play important roles in a broad range of aspects in cancer progression events such as tumorigenesis, invasion and metastasis, apoptosis control and angiogenesis. Therefore, using an antagonist molecule that is effective against HGF is expected to inhibit these biological activities of HGF.
Patent document 1 describes a method of preparing a humanized neutralizing monoclonal antibody against HGF using mouse L2G7mAb.
However, a monoclonal antibody from a tissue culture supernatant, as described in patent document 1, usually contains complex impurity components derived from the cell culture broth; for pharmaceutical use, it is essential to obtain a highly purified antibody deprived of these impurity components. A wide variety of methods of antibody purification have been proposed so far, many of which are based on chromatography. Reported methods of treatment by chromatography are anion exchange chromatography, cation exchange chromatography, and hydrophobic chromatography.
In recent years, affinity chromatography with protein A or protein G has been widely used as a convenient method to obtain high purity in the isolation and purification of antibodies, and is particularly widely known in antibody production on industrial scales.
In another reported method, gel filtration chromatography is performed with an appropriate amount of arginine added to an aqueous buffer solution of a chromatogram developing solvent during treatment of a hydrophobic protein and the like, including an aggregate of associated particles, so as to weaken the possibly occurring unwanted interaction between the protein and the column packing material, whereby an aggregate of associated particles, hydrophobic protein and hydrophobic peptide are more quantitatively recovered (patent document 2).    Patent document 1: WO2007-115049    Patent document JP-A-2006-242957